Automatic gas-burner.



PATENTED DEC. 15, 1903.

W. (LDUDLEY.

AUTOMATIC (44s BURNER.

APPLICATION FILED AUG. 2, 1901.

N0 MODEL.

m: Mmms puns co, Pnmoumm waivz-w'ro rrnn dra ns iatented December 15,1903.

WALTER J. DUDLEY, OF BANGOR, MAINE.

ATOMATIC GAS BURNER.

SPECIFICATION forming part of Letters Patent No. 747,244, dated December15, 1903.

Application filed August 2,1901. Serial No. 70,686. (No model.)

To all whom it may concern:

Be it known that I, WALTER J. DUDLEY, a citizen of the United States,residing at Ban gor, in the county of Penobscot and State of Maine, haveinvented a new and useful Automatic Gas-Burner, of which the followingis a specification.

My invention relates to an improved automatic or safety-burner forpreventing the continued escape of unlighted gas.

The device constituting this invention consists in part in a tubearranged to have one end heated by the gas-flame, while the other ordistant end is curved and arranged to normally close the gas-inlet ofthe burner. This tube is filled with a fluid easily expansible orvaporizable by heat, such expansion creating a stress in the tube andcausing the curved portion to expand or assume a flattercurve,andtherebyuncoverthegas-inlet. The principle upon which this tubeis constructed and operates is that of the ordinary Bourdon tube used inpressure-gages and some metallic thermometers, and this tube will behereinafter referred to asa Bourdon tube. An arrangement whereby thetube and its contained fluid are heated not by the direct flameimpinging thereon, but by means of a solid projection or pin secured tothe tube and projecting into proximity to the flame, thus forming aconduit for the heat, is also a part of my invention,the object being toavoid excessive heating of the fluid. A method of filling the tube witha fluid of small expansive coefficient at the temperatures to which itis exposed in use with the exception of. a portion nearest the source ofheat, which is filled with ahighlyexpansible fluid, forms a part ofmyinvention,the object being to avoid the excessive strains consequentupon the heating of a comparatively large body of easily-expansiblefluid, as the burner becomes heated throughout when lighted for longperiods.

A form of my burner is shown in the accompanying drawings, in Which--Figure 1 is a vertical section taken through the center of a burner.Fig. 2 is a horizontal section on line W X; and Fig. 3 is a similarsection on line Y Z, Fig. 1. a

The base A of the burner is threaded at a to screw onto the fixture andexpanded above into a cup at, which is shouldered at 0, to receive andsupport the annular plate B, to which latter are attached the automaticdevices controlling the admission of gas to the burner-pillar b, saidpillar being secured to plate B, as shown. The upper edge of cup a maybe spun over plate 13 to make a tight joint. A heating-chamber, shown asa tubular ring (1, supported on an upright tube D, encircles theburner-pillar nearits upper end, anda heat-conductor, such as a pin dsecured (preferably brazed) to said tubular ring, projects upwardopposite one end of the gasslit 0 in burner-tip O in such manner thatthe free end of said pin is continuously heated by the gas-flame, andheat is thus conducted from the flame to the tubular ring (1, the amountconducted depending on the diameter and length of pin d and its positionrelative to the gas-flame. The bore of tubular ring (1 is continuouswith that of tube D. Tube D is inserted at (1 into an elbow d, whichlatter passes through and is secured to plate B. A thin flat elasticBourdon tube F, curved, as shown, to conform somewhat to the shape ofthe interior circumference of cup or, is secured at one end atf to elbow01, while its free end is embedded in a flat-faced block f, the cavityof tube f being continuous with that of elbow d, tube D, and tubularring d. The whole series of tube-cavities is filled with fluid, of whichat least the portion contained in ring 61 must be easily expansible orvapo rizable by heat, but it is preferable to have the remaining fluidpractically non-expansible at temperatures to which it is exposed inuse. the fluid is hermetically sealed within the tube-cavities.

The face of block f when the burner is cold rests against an arm I,closing a gas-portql in said arm and constituting a valve controllingthe supply of gas to the burner-pillar. Arm I projects from a hollowplug H, said plug being closed at the lower end and with the upper endopening into the cavity of the burnerpillar b, as shown, and port '1; iscontinuous with the hollow of said plug. Plug H is shouldered andriveted at 71 into the center hole of plate B, and gas entering pillar bmust first pass through port 1' in arm I and the cavity of plug H. PlugH is secured to plate B so After filling the tubes as to turn stifflyand is provided with aslot -h, so that it can be turned by ascrew-driver fluid as will damage the burner.

and the relation of arm I to block f (or the valve to its seat) beeasily adjusteda matter of practical importance.

In a properly-adjusted burner when cold tube F will assume the positionof Fig. 2, resting against arm I and closing port 7;, and in thisposition gas cannot pass to the burnertip if turned on by the usualthumb-cock.

To light the burner, a flame, of a match usually, must be placed beneathtubular ring (1, which will expand or volatilize the contained fluid andcreatea pressure in tube F, and when this pressure has sufficientlyincreased tube F yields by expanding or straightening its curvature, asshown in Fig. 3, thereby moving block f away from arm I and uncoveringport 2', thus admitting gas to the burner-pillar b and tip 0, where itbecomes ignited by the same flame that heated ring (1. The continuedheating of ring 01 by the heat conducted to it by pin 01 keeps upsufficient pressure to retain tube F expanded and the gas-port 'i open.If The flame becomes extinguished from any cause, the resiliency of tubeF will cause it to assume the normal position, asin Fig. 2, as the tubecools off and the pressure of the contained fluid diminishes, therebybringing block f over port z'and shuttingoff the gas from theburner-tip.

I find it very easy to so proportion pin (1 that the amount of heatconveyed by it to tubular ring 01 is just enough to keep said ringheated to the proper degree and no more, as a balance is struck betweenthe amount of heat received and that radiated by the ring and itsimmediate connections, which is practically constant. This plan ofheating a fluidcontaining chamber indirectly is of greatimportance, asit is otherwise impossible to at times avoid such excessive overheatingof the This overheating is especially liable to occur when the gas isturned 'low down or when it is being blown about by a draft. In thislatter case the flame is liable to be blown directly upon thefluid-containing chamber and either rupture it or so strain the movablemember that the burner becomes useless. The plan of heating through aconduit of limited conducting capacity avoids all such danger.

It will be noticed on inspecting Fig. 3 that when tube F has expanded tofully uncover port '5 the outer curve of said tube osculates quiteclosely with the interior circumference of cup at. This is so arrangedfor the purpose of preventing tube F from exceeding its elastic limit inexpanding under pressure, so that it will surely return to the positionof Fig. 2 and close port'iwhen the burner is cold.

I prefer to use a steam-pressure in operating the burner, choosing forthis purpose a liquid of low boiling-point, such as alcohol or naphtha,and the tube-cavities may be completely filled therewith with goodresults; but it is preferable to fill only ring (1 with such a liquidand to fill the remaining spaces with a liquid not boiling at thetemperatures to which it is exposed in use, as after burningfor aconsiderable time the entire burner may become heated, and it isdesirable to avoid the excessive pressure that would be caused therebyif all the tube-cavities were filled with a pressure-generating fluid.

It is of course necessary to use two liquids that will not mix-such asnaphtha and water, for instance.

As liquids of low boiling-points usually are of low specific gravities,there is no liability of the two liquids changing places in use, as thelighter and more volatile fluid will naturally remain at the top; butevenif the burner be inverted, as in transport, the two liquids will notchange places, as the tubes are so small that adhesion and cohesion arestronger than gravity in this case.

It is evident that if the tubes are completely filled with a liquid ofhigh expansive coefiicient 'at temperatures below the boiling-point ofsuch liquid the'burner can be operated without the generation of asteam-pressure.

In using the combination of the two fluids in the way described I do notwish to confine my claims to the particular form of burner vherein shownand described. Other forms of automatic burner can be adapted to usethis principle, such as that class in which the valvecontrolling devicecontains a flexible diaphragm which is pressed in and out by thepressure generated in a miniature boiler or heating-chamber near thegas-flame.

I am aware that a curved sealed tube containing an expansible fluid andoperating a valve when subjected to varying temperatures has beenpreviously used in connection with steam-traps, and therefore I do notbroadly claim the adaptation of the Bourdon tube to operating-valves,but

What I do claim is- 1. In an automatic gas-burner; the combination'witha valve-seat; of a Bourdon tube carrying a Valve to cooperate with saidvalveseat; a fluid contained in said tube; a'heating-chambercommunicating with said tube but at some distance therefrom, and adifferent fluid contained in said heating-chamber, substantially asdescribed.

2. In an automatic gas-burner; the combination with a valve-seat; of aBourdon tube carrying a valve to-cooperate with said val veseat; a fluidcontained in said tube; a heating-chamber communicating with said tubeand containing a different fluid; and a heatconductor close to theburner-orifice and leading to said heating-chamber.

8. The combination with a valve-seat; of a Bourdon tube carrying a valveto cooperate with said seat; a fluid contained in said tube and meansfor conducting the heat of the flame to said fluid; and means foradjusting the position of said valve-seat relative to the valve,substantially as described.

4. The combination with a valve-seat; of a Bourdon tube carrying a valveto cooperate with said seat; a heating-chamber communieating with saidtube but at some distance therefrom; a fluid of relatively highcoeflicient of expansion contained-in said heatingchamber; and a fluidof relatively low coefficient of expansion contained in said tube,substantially as described.

5. The combination with avalve-seat; ofa Bourdon tube carrying a valveto cooperate with said seat; means for exerting pressure within saidtube; and -a stop substantiallyconforming to the curvature of saidtube,substantially as described.

6. The combination withaburnerofavalve for closing the gas passagethereof and a flexible curved tube containing a fluid for actuating saidvalve and arranged to operate when the burner is heated and therebymaintain the valve in an open position until the burner cools,substantially as described.

7. The'combination with aburner ofavalve for closing the gas-passagethereof and a flexible curved tube situated within the burner andcontaining a fluid for actuating said valve and arranged to operate whenthe burner is heated and thereby maintain the valve in an open positionuntil the burner cools, substantially as described.

8. The combination withaburnerofavalve for closing the gasrpassagethereof and a flexible curved tube containing an expansive fluid foractuating said valve and arranged to operate when the burner is heatedand there: by maintain the valve in an open position until the burnercools, substantially as described.

9. A burner containing means for automatically preventing the flow ofgas therethrough when the flame is extinguished, said means including,as the actuating element thereof, a flexible curved tube containing afluid the pressure of which is increased when the burner is heated,substantially as described.

10. The combination with a burner of a thermally-actuated valvecontrolling or closing device therefor, and said device including aflexible curved tube having therein an expansible fluid and means,exposed to the atmosphere, for conducting a limited amount of heat tosaid valve-controlling device so as to avoid rupture of the parts whenexpansion occurs, substantially as described.

11. The combination with a burner having a space or chamber in its bodyportion, a curved flexible tube containing an expansible fluid disposedwithin said chamber, a valve also disposed within said chamber andarranged to be actuated by said tube, and a second tube in communicationwith said flexible tube at one end and adapted to receive heat from theflame of the burner at the other end, substantially as described.

12. The combination with a burner having a space or chamber in its bodyportion, a curved flexible tube containing an expansible fluid disposedwithin said chamber, a valve and an oscillatory hollow blockcommunicating with the burner-passage and carrying a valve-seat alsodisposed within said chamber and arranged to be actuated by said tube,and a second tube in communication with said flexible tube at one endand adapted to receive heat from the flame of the burner at the otherend, substantially as described.

WALTER J. DUDLEY.

